PMDATRACE(1)PMDATRACE(1)NAMEpmdatrace - application-level transaction performance metrics domain
agent
SYNOPSIS
$PCP_PMDAS_DIR/trace/pmdatrace [-d domain] [-l logfile] [-A access] [-I
port] [-M username] [-N buckets] [-T period] [-U units]
DESCRIPTIONpmdatrace is a Performance Metrics Domain Agent (PMDA) which exports
transaction performance metrics from application processes which use
the pcp_trace library described in pmdatrace(3).
A brief description of the pmdatrace command line options follows:
-d It is absolutely crucial that the performance metrics domain num‐
ber specified here is unique and consistent. That is, domain
should be different for every PMDA on the one host, and the same
domain number should be used for the same PMDA on all hosts.
-l Location of the log file. By default, a log file named trace.log
is written in the current directory of pmcd(1) when pmdatrace is
started, i.e. $PCP_LOG_DIR/pmcd. If the log file cannot be cre‐
ated or is not writable, output is written to the standard error
instead.
-A Host-based access control for pmdatrace. access must be either an
allow or deny specification, using either allow:hostspec:maxconns
or disallow:hostspec, where `allow' and `disallow' are keywords,
`hostspec' is a host specification conforming to the format used
by both pmcd(1) and pmlogger(1), and `maxconns' is the maximum
number of connections allowed from a given `hostspec'. Using a
maximum connections of zero specifies an unlimited number of con‐
nections for the accompanying `hostspec'.
-I Communicate with pcp_trace clients via the given Internet port.
This can alternatively be specified by setting $PCP_TRACE_PORT in
the environment to some valid port number (use of the -I option
overrides this). The default port number is 4323.
-T period defines the aggregation period used to compute the recent
averages and extrema. Specified as a time interval using the syn‐
tax described in PCPIntro(1) for the common -t PCP argument, e.g.
30 seconds or 1 min. The default is 60 seconds.
-M User account under which to run the agent. The default is the
unprivileged "pcp" account in current versions of PCP, but in
older versions the superuser account ("root") was used by default.
-N Internally, the aggregation period is divided into bucket divi‐
sions, and the rolling average is recomputed every period/bucket
seconds. For example, the defaults correspond to -T 60 and -N 12,
which means the average is recomputed every five seconds for a
period covering the prior 60 seconds.
-U This option allows the dimension and scale associated with the
observation value metric to be configured. units is a comma-sepa‐
rated string of six integer values, which are the space dimension,
time dimension, count dimension, space scale, time scale, and
count scale, respectively. The default dimension and scale is
``none'', which is equivalent to presenting ``0,0,0,0,0,0'' as the
argument to -U. The units associated with a metric are most eas‐
ily viewed using the -d (metric description) option to pminfo(1).
The Install script described below steps through this option quite
explicitly, so it is recommended that the Install script be used
for building up the units specification.
Essentially, the exported metrics provide statistics on the time for
completion of each transaction, and an average count of transactions
completed and watch points passed over a given time period.
INSTALLATION
In order for a host to export the names, help text and values for the
Trace performance metrics, do the following as root:
# cd $PCP_PMDAS_DIR/trace
# ./Install
If you want to undo the installation, do the following as root:
# cd $PCP_PMDAS_DIR/trace
# ./Remove
pmdatrace is launched by pmcd(1) and should never be executed directly.
The Install and Remove scripts notify pmcd(1) when the agent is
installed or removed.
FILES
$PCP_PMCDCONF_PATH
command line options used to launch pmdatrace
$PCP_PMDAS_DIR/trace/help
default help text file for the trace metrics
$PCP_DEMOS_DIR/trace/*
example programs which use the pcp_trace library
$PCP_PMDAS_DIR/trace/Install
installation script for the pmdatrace agent
$PCP_PMDAS_DIR/trace/Remove
undo installation script for pmdatrace
$PCP_LOG_DIR/pmcd/trace.log
default log file for error messages and other information
from pmdatracePCP ENVIRONMENT
Environment variables with the prefix PCP_ are used to parameterize the
file and directory names used by PCP. On each installation, the file
/etc/pcp.conf contains the local values for these variables. The
$PCP_CONF variable may be used to specify an alternative configuration
file, as described in pcp.conf(5).
SEE ALSOPCPIntro(1), pmcd(1), pmtrace(1), PMAPI(3) and pmdatrace(3).
Performance Co-Pilot PCP PMDATRACE(1)
